Governing mechanism for elastic-fluid turbines.



M. M. PEARSON.

GOVERNING MECHANISM FOR ELASTIC FLUID TURBINES.

APPLICATION rnnn' AUG, 18. 1911.

1,054,935. v Patented'Mar.4,1913.4

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Hissqttorney.

Millard MPearson,

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Patented Mar. 4, 1913.

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M. M. PEARSON.

GOVERNING MECHANISM FOR ELASTIC FLUID TURBINES.

APPLIOA-TIOI'NTILED AUG.18, 1911.

M. M. PEARSON.

GOVERNING MECHANISM FOR ELASTIC FLUID TURBINES.

APPLIGATION FILED AUG. 18, 1911.

1,054,935, Patented Mar. 4, 1913.

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Inventor Millard MPeaF-Son IDBMW His J ttorneg.

UNITED. STATES PATENT OFFICE.

MILLARD M. PEARSON, or SCHENECTADY, NEW YORK, ASSIGNOR ro GENERALELECTRIC COMPANY, A conrona'rron or NEW ronx.

eovnnmne MncnA rsmron ELASTIC-FLUID 'IURLBINES.-

Specification of Letters Patent.

Patented Mar. 4., 1913.

Application filed August 18, 1911. Serial No. 644,835

To all whom it may concern:

Be it known that I, M nnano M. PEARSON, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Governing Mechanism forElastic-Fluid Turbines, of which the following is a specification.

This invention relates to elastic fluid turbines, and especially tothose of the low 1 pressure or mixed pressure types, in which exhauststeam from high pressure engines, or from heating or other industrialapparatus,'is utilized to drive the turbine. It is customary to controlthe flow of low pressure steam to the turbine by means of a valve of thebutterfly type, connected to an operating motor which is controlled bythe's'peed governor. In case the turbine races, an emergency governortrips certain automatic mechanism which closes the valve independentlyof the ordinary operating devices.

The purpose of the present invention is to improve the emergencymechanism for operating a butterfly valve of this kind.

In the accompanying drawings, Figure 1 is an end elevation of a mixedpressure turbine equipped with my butterfly valve, which s shown in itswide open position. Fig. 2

the valve is closed by the emergency gov ernor. Figs. 5 and 6 areperspective views of two of the levers forming part of the valveoperating mechanism. Fig. 7 is asectional elevation of the valve atright angles to Fig. 3. Fig. 8 is a section of a portion ofamodification. Fig. 9 is a side elevation of the same, partly brokenaway.

The turbine illustrated is a horizontal mixed pressure machine of theCurtis type, having a 'casing 1 supported on a base. 2. Certain nozzlesreceive low pressure steam through a large conduit 3, while another setof nozzles is supplied with steam at high pressure througha pipe enterinchest 5. The ow pressure conduit is controlled by a valve 6 of thebutterfly type, which is opened and closed by a crank arm 7 connectedbya rod 8 to a lever 9 which is arranged to be actuated by a motor 10controlled by the speed governor 11. This same motor also actuates thevalve or valves cona steam trolling the admissionof high pressure Isteam'to the turbine, although its operation of the low pressure andhigh pressure valves is not simultaneous but successive, opening -ria1lNo. 641,264, on which Patent 1,017 ,555

of February 13, 1912, was granted.

Referring again to the butterfly valve 6 it will be observed that itconsists of a disk preferably stiffened by transverse ribs 12 andsecured upon a spindle 13 which crosses it diametrically and forinsjournals 14 at each side of the disk. These journals are received insuitable steam-tight bearings in bosses 15 formed on the valve-casing 16. A bracket 17 is secured to one of said bosses, being preferablyprovided with a sleeve 18 concentric with the spindle '13; the bearing,

in the boss being enlarged to receive, said sleeve. The spindle extendsthrough said bracket and has keyed to it an arm 19, which in-thedrawings, is shown as standing at right angles to the valve 6; thoughits particular position is of course immaterial. Loosely mounted on thespindle and adjacent to the arm 19 is the crank 7, having on its hub ashoulder 20 which abuts against a lip 21 on the arm 19. The hub of thecrank 7 also has a notch 22, withv which engages a latch 23 pivoted onthe arm 19 and urged toward the hub of the crank 7 by a spring 24:seated at one end in a socket in a lug 25 on said arm, and at the otherend in a socket in the back of the latch. The crank is connected by therod 8 with the governing mechanisnn'so that said governor can vary theeffective opening of the valve to correspend with the demand for steam;the valve being normally locked to the/crank by the shoulder 20 and lip21, the notch 22 and latch 23.

Alongside of the crank 7 there is loosely journaled on the shaft 13 atripping plate 26 on which. is :1 lug 27 adapted to strike the latch 23and disengage-it from the notch 22 when said tripping plate is rotated.A strong spring 28 is attached at one end to said plate and at theother-end to ahanger 29 do )ending from the bracket 17. vThe .plate 18held up, so that the lug 27 is out of the normal range of movement ofthelatch 23, by means of a trip lever 30 provided with a hardened steelcatch 31 which engages a similar catch 32 on the plate. A small spring33keeps the catches in engagement. In this position the spring 28 isunder considerable tension. On the same rock shaft as the trip lever isan arm 34 connected by a rod. 35 with any suitable emergency governor,arranged to actuate said rod when the speed of the turbine runs up to anabnormal degree. The lever 30 also has a handle 36 so that it can betripped by hand, if de-' sired. The end of lever 34 is slotted to allowfor tripping by hand, independently of the emergency governor. I

The operation of the device is as follows :Under normal conditions, thespeed governing mechanism moves the rod 8 t0 and fro, and theinterlocked crank 7 and arm 19 turn the valve 6 to open or closeit moreor less, as determined by the governor. In case the engine begins torace, the emergency governor actuates the rod 35 and thereby trips thelever 30, disengaging the catches 31,, 32, and allowing the spring 28 topull the tripping plate suddenly to the position shown in Fig. 4. Inmoving to this position, the lug 27 strikes the latch 23, disengages itfrom the notch 22, and carries it and its arm 19 and with them the valve6 to the position shown in Fig. 4, thus closing the valve. The spring 28keeps the lug 27 pressed firmly against the latch 23, so that the valveis held tightly closed. To reset the tripping plate, a bar is insertedinto a socket in a boss 37 on one edge of said plate, whereupon adownward pull on said bar will return the plate to the position shown inFig. 3 and enable the catches 31, 32, to reengage and lock the plate.The reietting bar is indicated by dotted lines in the squared end 38 ofthe spindle 13 and openthe valve, thereby turning the arm 19 until thelatch 23 can again snap into the notch 22, and the parts will be readyfor normal operation as shown in Fig. 2.

The shoulder 20 and lip 21 form a safety device to enable the speedgovernor to close the valve even when the latch is disengaged from thearm 7, moreover, the shoulder forms a positive stop to prevent anybodyfrom opening the valve by applying a wrench to the squared end 38 ofthespindle when the governor has partly or wholly closed said valve; anaction which might cause the engine to run away and do considerabledamage.

In the inodification'shown in Figs. 8 an 9, the helical spring 28 isreplaced by a coiled spring 39 concentric with the spindle of the valve;said coiled spring being attached at one end to astud 40 on the trip-After the tripping plate has been reset, the attendant can apply awrench to ping plate and at the other to a stud 40' on a sleeve 41surrounding the hub of the tripping plate and provided with means foradjusting it angularly so as to vary the tension of the spring. This maybe accomplished by means of a segment gear 42 on said sleeve, meshingwith a worm 4:3 journaled in suitable bearings on the'bracket 17 andhaving a milled head 44 by which it can be turned to actuate said gearand vary the tension of the spring 39. In all other respects thismodification operates the-same as 'the construction shown in Figs. 1 to7 inelusive.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention together with theapparatus which I now consider to represent the best embodiment thereof;but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention can be carried out by other means.

WVhat I claim as new and desire to secure by Letters Patent of theUnited States, is,

1. Governing mechanism for controlling a butterfly valve comprising anarm fixed on the outer end of the spindle of said valve, a crank looseon said spindle that is arranged on the inner side of the arm and has anotch "in its hub, a latch pivoted on said arm and engaging with saidnotch, a spring-actuated tripping plate loose on said spindle and actingto disengage said latch and turn said arm and valve, and a trippinglever for locking said tripping plate.

2. Governing mechanism for controlling a butterfly valve comprising anarm fixed on the outer end of the spindle of said valve, a spring latchpivoted on said arm, a crank loose on said spindle that is arranged onthe inner side of the arm and has a notch in its hub engaged by saidlatch, a tripping plate loose on said spindle and arranged on the innerside of the crank, a spring biasing said plate to turn, alug onsaidplate adapted to trip said latch, a catch on said plate, and a pivotedtripping lever engaging therewith.

3. Governing mechanism for controlling a rotary'valve, comprising an armfixed on the spindle of said valve and having a lip, a spring latchpivoted on said arm, a crank loose on the spindle and having a shoulderengaging with said lip and a notch engaged by said latch, and aspring-actuated tripping-plate for disengaging said latch and turningsaid arm and valve.

4. The combination with a steam turbine having a speed governor, anemergency governor, and a butterfly valve for regulating the admissionof steam to the turbine that is controlled by said governors, ofmechanism for controlling the butterfly valve, comprising an arm fixedon the spindle of said valve, a crank loose on said spindle andcontrolled by the speed governor, detachable connec- -a tripping levercarried by said shaft and engaging with the catch on the tripping plate,and an arm on said rock shaft controllable by said emergency governor.

5. Governing mechanism for controlling a butterfly valve comprising anarm fixed on the spindle of said valve, a crank loose on said spindle, alatch locking said arm to said crank, a trippingplate pivoted on saidspindle, a sleeve concentric with said spindle and carrying a segmentgear, a worm meshing with said gear, a coiled spring attached at one.end to said plate and at the other to said sleeve, and a tripping leverfor releasing said tripping plate.

6. Governing mechanism for controlling a rotary valve comprising aspindle for the valve, an arm fixed on the spindle and having a lip onits hub portion, a latch carried by the arm, a crank loosely mounted onthe spindle adjacent to the arm, the hub portion of the crank having ashoulder for engaging said lip and also a device for engaging the latch,a tripping plate for releasing the latch that is mounted for rotationabout the spindle, means. tending to turn the plate, and a device fornormally preventing the plate from turning. I

7. Governing mechanism for controlling arotary valve comprising aspindle for the valve, an arm fixed on the outer end of the spindle, alatch pivoted to the inner side of the arm, a crank loosely mounted onthe spindle adjacent to the inner side of the arm and provided with adevice for engaging the latch, a tripping plate loosely mounted on thespindle adjacent to the inner side of the crank and havin means adaptedto trip the latch, means ten ing to turn the plate, and a devicefor'normally preventing it from turnmg.

a rotary valve comprising a spindle having its outer end shaped toreceive a wrench, an arm fixed to the outer portion of the spindle nextto said shaped end, a latch mounted on the inner side of the outer endof the arm, a crank loosely mounted on the spindle adjae nt the innerside of the arm and provided wTith a notch to receive the end of thelatch, a tripping plate loosely mounted on the spindle adjacent to. theinner side of the crank and provided with a laterally projecting lug,means that tends to turn the tripping plate and bring the lug intoengagement with the latch to release the crank and arm, and a latch thatnormally holds the plate from turning.

In witness whereof, I have hereunto set my hand this 17th day of August,1911.

MILLABD M. PEARSON.

8. Governing mechanism for controlling

